Cod sursa(job #1111028)

Utilizator CosminRusuCosmin Rusu CosminRusu Data 18 februarie 2014 16:31:44
Problema Range minimum query Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.94 kb
#include <fstream>
#include <iostream>
#include <vector>
#include <bitset>
#include <string.h>
#include <algorithm>
#include <iomanip>
#include <math.h>
#include <time.h>
#include <stdlib.h>
#include <set>
#include <map>
#include <string>
#include <queue>
#include <deque>

using namespace std;

const char infile[] = "rmq.in";
const char outfile[] = "rmq.out";

ifstream fin(infile);
ofstream fout(outfile);

const int MAXN = 100005;
const int MAXLG = 20;
const int oo = 0x3f3f3f3f;

typedef vector<int> Graph[MAXN];
typedef vector<int> :: iterator It;

const inline int min(const int &a, const int &b) { if( a > b ) return b;   return a; }
const inline int max(const int &a, const int &b) { if( a < b ) return b;   return a; }
const inline void Get_min(int &a, const int b)    { if( a > b ) a = b; }
const inline void Get_max(int &a, const int b)    { if( a < b ) a = b; }

int RMQ[MAXLG][MAXN], Log[MAXN];
int a[MAXN];
int N, M;
/// RMQ[i][j] = min(i.... i + 2 ^ j - 1) = min(i .... i + 2 ^ ( j - 1 ) - 1) + min(i + 2 ^ ( j - 1) ... i + 2 ^ ( j - 1 ) + 2 ^ ( j - 1) - 1]

int main() {
    fin >> N >> M;
    for(int i = 1 ; i <= N ; ++ i) {
        fin >> a[i];
        RMQ[0][i] = i;
    }
    for(int i = 2 ; i <= N ; ++ i)
        Log[i] = Log[i >> 1] + 1;
    for(int i = 1 ; (1 << i) <= N ; ++ i) {
        for(int j = 1 ; j + (1 << i) - 1 <= N ; ++ j) {
            RMQ[i][j] = RMQ[i - 1][j];
            int l = (1 << (i - 1));
            if(a[RMQ[i][j]] > a[RMQ[i - 1][j + l]])
                RMQ[i][j] = RMQ[i - 1][j + l];
        }
    }
    for(int i = 1 ; i <= M ; ++ i) {
        int x, y;
        fin >> x >> y;
        int diff = (y - x + 1);
        int log = Log[diff];
        int Ans = RMQ[log][x];
        if(a[Ans] > a[RMQ[log][y - (1 << log) + 1]]);
            Ans = RMQ[log][y - (1 << log) + 1];
        fout << a[Ans] << '\n';
    }
    fin.close();
    fout.close();
    return 0;
}